EAGER: Revisiting Catalyst Design in Heat-Exchanger Microreactors

摘要PI：Wilhite，Benjamin机构：德克萨斯州A& M提案编号：1319142职务：EAGER：重新审视热交换器微型反应器中的催化剂设计天然气（甲烷）到氢气和/或合成气的高效催化转化仍然是新兴清洁能源行业和现有石化和天然气市场的关键挑战。开发可从天然气操作的高效、中等规模的高纯度氢发生器将允许将现有天然气资源立即转化为无排放的氢燃料。实现有效地将甲烷转化为合成气（用于随后转化为合成原油）的成本效益高的技术有助于以丰富的天然气直接替代日益减少的石油资源，而对现有的石化基础设施的破坏最小。热交换器微反应器，能够有效的热耦合放热甲烷燃烧与吸热蒸汽重整提供了一个强大的平台，以满足这些挑战。目前的热交换器微反应器设计采用直接放置在微通道壁上的薄催化涂层，使得吸热（蒸汽重整）和放热（燃烧、部分氧化）过程之间的热传递除了预期的热传递介质（即微反应器壁）之外，还经由穿过两个催化剂膜的传导发生。这代表了与催化剂颗粒设计的微妙但显著的偏离，因为热量可以从催化剂膜的中心供应或移除（与颗粒设计中存在的绝热中心条件相反）。迄今为止，热交换器微反应器已经采用均匀的薄催化剂膜来防止任何内部传热或传质阻力的发展。私家侦探？在膜微反应器设计领域的前期研究成果表明，在催化剂膜中引入显著的传质阻力可以在整个系统性能上取得突破，这是一个为期12个月的探索性努力，以确定旨在为热交换器微反应器中使用的催化剂膜引入显著的传热阻力的非常规催化剂设计是否可以在催化剂和热利用方面取得突破。这一假设将探讨通过详细的计算流体动力学（CFD）模拟的工业radialmicroreactor（RMR）正在开发的这一应用程序。用于改进和验证CFD模拟的实验数据将由Power Energy，Inc.提供。来支持这项基础研究工作。该研究既新颖又高风险/高收益，因为PI打算在催化剂和反应器尺度上引入显着的传热阻力来操纵反应传输现象。因此，该设计策略与旨在最大限度地减少运输限制的传统催化剂和反应器设计原则以及热交换器微反应器设计中的当前实践形成鲜明对比。智力优势：在该奖项下获得的基础知识预计将对微反应器和过程强化社区具有广泛的价值。基本分析和设计模拟将通过在同行评审的研究期刊上发表文章进行传播，这些期刊强调反应堆设计，包括化学工程杂志、化学工程科学、工业工程化学研究和AIChE杂志。研究结果也将通过在ACS和AIChE国家会议上的研究报告传播。更广泛的影响：天然气或沼气制氢的突破性进展直接支持可持续能源经济的发展，并具有相称的环境和经济优势。氢气或合成气技术的进步满足了石化和天然气行业的关键工业需求，并具有相应的经济优势。

ABSTRACTPI: Wilhite, Benjamin Institution: Texas A&MProposal Number: 1319142Title: EAGER: Revisiting Catalyst Design in Heat-Exchanger MicroreactorsThe efficient catalytic conversion of natural gas (methane) to hydrogen and/or synthesis gas remains a critical challenge for both emerging clean energy industries and existing petrochemical and natural gas markets. Development of efficient, meso-scale high-purity hydrogen generators operable from natural gas would allow immediate conversion of existing natural gas resources to an emission-free hydrogen fuel. Realization of cost-effective technologies for efficiently converting methane to synthesis gas (for subsequent conversion to synthetic crude oil) facilitates the direct substitution of abundant natural gas for dwindling petroleum resources with a minimal disruption to existing petrochemical infrastructure. Heat-exchanger microreactors, capable of efficient thermal coupling of exothermic methane combustion with endothermic steam reforming provide a robust platform for meeting these challenges. Current heat-exchanger microreactor designs employ thin catalytic washcoatings placed directly over the microchannel wall, such that heat transfer between endothermic (steam reforming) and exothermic (combustion, partial oxidation) processes occur via conduction across both catalyst films, in addition to the intended heat transfer medium (i.e. microreactor wall). This represents a subtle yet significant departure from catalyst pellet designs, as heat may be supplied or removed from the center of the catalyst film (as opposed to the adiabatic center condition present in pellet designs). To date heat exchanger micoreactors have employed uniformly thin catalyst films to prevent the development of any internal heat- or mass-transfer resistances. The PI?s previous research results in the field of membrane microreactor design have illustrated that introducing significant mass transport resistances in catalyst films can provide breakthroughs in overall system performance.This is a 12-month exploratory effort to determine whether unconventional catalyst designs aimed at introducing significant heat-transport resistances to catalyst films employed in heat exchangermicoreactors can achieve breakthroughs in catalyst and heat utilization. This hypothesis will be explored through detailed computational fluid-dynamic (CFD) simulations of an industrial radialmicroreactor (RMR) under development for this application. Experimental data for refining and validating CFD simulations will be provided by Power & Energy, Inc. in support of this fundamental research effort. The research is both novel and high-risk / high-gain, as the PI intends to introduce significant heat-transfer resistances at the catalyst- and reactor-scales to manipulate reaction-transport phenomena. The design strategy thus stands in contrast to traditional catalyst and reactor-design principles aimed at minimizing transport limitations, as well as current practices in heat exchanger microreactor design.Intellectual Merit: Fundamental knowledge gained under this award is expected to be of broad value to the microreactor and process-intensification community. Fundamental analysis and design simulations will be disseminated through publication in peer-reviewed research journals emphasizing reactor design, including Chemical Engineering Journal, ChemicalEngineering Science, Industrial & Engineering Chemistry Research and AIChE Journal. Findings will also be disseminated through research presentations at ACS and AIChE national meetings.Broader Impact: Breakthroughs in hydrogen production from natural gas, or biogas, directly support the development of a sustainable energy economy with commensurate environmental and economic advantages. Advances in hydrogen or synthesis gas technologies meet critical industrial needs in the petrochemicals and natural gas industries, with commensurate economic advantages.